Method of making separable fastener sliders



y 1937- G. SUNDBACK 2,079,722

METHOD OF MAKING SEPARABLE FASTENER SLIDERS Filed July 15, 1935 'INVENTOR.

Gideon Surzdbac'lz' BY A RNEYS.

Patented May 11, 1937 UNITED. STATES PATENT OFFICE METHOD OF MAKING SEPARABLE FASTENER SLIDERS Application July 15, 1933, Serial No. 680,575

3 Claims.

This invention relates to separable interlocking fasteners of the type having a series of fastener members which are engaged and disengaged by movement of a slider along the rows of fastening members.

The invention is particularly concerned with an improved slider and an improved method of making the same.

Sliders for separable slide fasteners have been made from metal and in order to keep the cost down to a minimum the slider is built up from sheet metal blanks in various ways or the slider is pressed and bent to the desired shape from strip metal.

separable interlocking fasteners have been made from non-metallic materials, for example pyroxylin and phenolic condensation products. It is desirable to make the sliders for such fasteners of the same material. While it might be possible to mold such sliders to form it is believed that that method would have disadvantages in actual production. It would require expensive equipment and would be difficult to control accurately.

According to the present invention, a slider is provided which has all the requisites of a good slider, possessing the maximum stiffness and strength and the most compact and pleasing appearance possible.

Since it is difficult to bend and shape nonmetallic materials of the character mentioned, my invention has for its principal object to provide a method of making sliders which will avoid all bending and forming operations.

More particularly according to the invention, a slider is built up from pieces of non-metallic material which can easily be shaped by any suitable method, preferably by cutting from flat piecesof material. These pieces are placed in the proper relation and attached together by sticking. Sticking as used herein means causing the parts to adhere together by the use of cement, glue or the like, or by softening the surfaces of the elements.

In the accompanying drawing, I have shown for purposes of illustration, two embodiments which my invention may assume in practice. In this drawing:

Fig. 1 is a perspective view of a pair of slider blanks having grooves cut therein;

Fig. 2 is a view of a spacer member used in this embodiment of my invention;

Fig. 3 shows the step of assembling the various pieces;

Figs. 4, 5, 6 and 7 show the fiat wing, flange,

wedge and pull attaching member respectively, each constituting separate pieces of a slider;

Fig. 8 illustrates the assembly of the flanges and wedge piece with one of the wings; and.

Fig. 9 shows a complete slider.

The double wing blank of hour-glass configuration shown in Fig. 1 can be formed from a flat piece having the over-all thickness of the part illustrated. It is provided on each end with a Y-shaped groove having a lower branch II- and upper diverging branches l2, with a wedge or triangular lug l3 between them which can conveniently be formed by cutting two arcuate slots or grooves corresponding to the curvature of the pair of side flanges and overlapping at the center of the blank. When formed in this manner, the wings also have integral side flanges I4 which have a suitable curve or other outline desired in the finished slider. This twin blank is cut apart along the dotted line l5 to provide upper and lower wings l6, H, which may be assembled with a spacer member I8 between the triangular lugs 13, to form a complete slider body. The spacer member I8 is of sufficient thickness to provide the desired spacing between the flanges of the slider. If the parts are made of soluble material one convenient way of sticking the parts together is to soften the piece l8 in a solvent such as acetone, and then press it between the wings. It will weld itself integrally with the triangular lugs l3 and form a very strong connection. If insoluble materials are employed, the parts may be stuck together by suitable cement or glue, or heat may be applied in the case of some materials to effect the softening of the parts sufliciently to cause them to adhere to each other.

In order to complete the slider, it is desirable to have a pull attaching member, herein a loop [9, Fig. 7, which serves to connect a pull tab 20 to the slider body. The piece i9 is assembled with the slider body in the same manner as the other pieces for example, by sticking it on with solvent.

In the other illustrated embodiment, the various parts of the slider are formed from flat stock. A fiat keystone-shaped wing 2lis illustrated in Fig. 4, and the flange pieces are indicated at 22. The spacer block 23 has a thickness which would be equal to the combined width of the flange pieces 22 and also the desired spacing between the flanges. The wedge-shaped block 23 and flange pieces 22 are assembled as illustrated in Fig. 8 by a sticking process of the same character as that above described. In order to complete the slider, another pair of flange pieces will be stuck to a flat wing which will then be stuck in place on the wedge block 23.

As a result of my invention it will be observed that a method of making sliders has been devised which will produce the strongest and most compact slider possible, from non-metallic material at a minimum of expense. All bending and forming operations are avoided so that it is unnecessary to use heat and forming dies which are expensive and difficult to control in production.

While I have shown and described in this application two embodiments which my invention may assume in practice, it will be understoodthat these embodiments are merely for the purposes of illustration and description and that various other forms may be devised within the scope of my invention as defined in the following claims.

What I claim as my invention is:

1. The method of making sliders of non-metallic material for separable fasteners of the class described comprising preparing a blank of generally keystone-shape, milling a Y-shaped groove in one side of the blank and sticking two of the milled parts together with the grooves facing each other to form a Y-shaped channel.

2. The method of making sliders of non-metallic material for separable fasteners of the class described comprising preparing a fiat blank of keystone shape, cutting a Y-shaped groove in one face of said blank leaving lateral flanges and a wedged-shaped lug between the diverging branches of the groove, assembling two such grooved members together with the grooves facing one another and with a spacer between said lugs, and sticking said lugs and spacer together to form a complete slider.

3. The method of making sliders for separable fasteners which consists in cutting a pair of overlapping arcuate grooves in an hour-glass shaped blank to form side flanges and intermediate wedges, severing the blank into two symmetrical halves each having a Y-shaped channel and sticking the two halves together with the grooves facing each other to form Y-shaped passages for interlocking elements.

GIDEON SUNDBACK. 

